Humoral factors such as inflammatory cytokines are deeply involved in causes of inflammatory diseases such as systemic lupus erythematosus, rheumatoid arthritis, multiple sclerosis, ulcerative colitis and Crohn's disease. Attempts are being made to treat inflammatory diseases by inactivating these humoral factors with biologicals such as low molecular drugs and antibodies. However, each of these humoral factors does not act alone on the site of inflammation. Plural humoral factors synergistically act to cause development and progression of inflammatory diseases. Thus, recent interest has focused on leukocytapheresis in which activated leukocytes per se as the source of humoral factors are removed.
Leukocytapheresis is a therapeutic method by blood purification wherein blood is collected from the vein and activated leukocytes are removed therefrom using, for example, a column filled with a carrier for adsorption, followed by returning the purified blood into the vein in the opposite side. Leukocytes can be roughly divided into 3 types, that is, granulocytes, monocytes and lymphocytes. Since leukocytes directly involved in inflammation caused by inflammatory diseases are considered to be granulocytes and monocytes, a carrier that selectively adsorbs granulocytes (JP 2501500 B2) and a carrier that selectively adsorbs both activated granulocytes and monocytes as well as inflammatory cytokines (JP 2006-312804 A and JP 7-080062 A) have been developed.
On the other hand, lymphocytes are also known to be indirectly involved in inflammation caused by inflammatory diseases. There is also a view that not only granulocytes and monocytes, but also lymphocytes should be removed by adsorption to achieve rapid healing of a severe inflammatory disease in a patient. Therefore, a carrier that can adsorb all of the 3 types of leukocytes, that is, granulocytes, monocytes and lymphocytes, has also been developed (JP 60-193468 A and JP 2001-310917 A).
However, the carrier that allows adsorption of all of the 3 types of leukocytes, that is, granulocytes, monocytes and lymphocytes, is composed of a non-woven fabric prepared from an ultrafine fiber, which non-woven fabric has a high bulk density. Since most blood components other than erythrocytes are filtered out and pressure loss occurs during blood circulation, safety problems such as stopping of the circulation and leakage of blood have been pointed out. On the other hand, although a powerful leukocyte-removing carrier that can adsorb not only all of the 3 types of leukocytes, but also inflammatory cytokines has been demanded, no successful development of such a carrier has been reported so far because of difficulty in overcoming the above problem.
It could therefore be helpful to provide a carrier for blood component adsorption which can remove leukocytes including all of granulocytes, monocytes and lymphocytes by adsorption while suppressing occurrence of pressure loss during blood circulation, which carrier can also remove inflammatory cytokines by adsorption at the same time.